i just removed my fuel tank , going to replace my fuel pump and noticed and alittle wetness on top of the filler neck where it goes inside the tank, i cleaned the area and noticed a hair line crack at the top , since my tank is in real good condition and dont want to replace it , i was planning on flushing out the tank with water a few time , what kind of solder did the factory use on the filler neck ? i have a couple rolls of stay-brite silver bearing solder in my work truck , do you guys think that would be good to resolder with mapp gas ?

 

There was actually a recall in some years for that exact issue. I would think you would be okay soldering the tank. I have soldered fuel tanks using acid core solder. Just be sure to get all of the fuel trace and vapors out of it. You can also pump the tank full of argon, CO2, or nitrogen and any vapors left over will not combust due to the inert gas.